Corneal endothelium microscopes are used to examine and photograph the corneal endothelium of an eye in vivo. Such instruments often permit the detection of endothelium damage or disease which may not be seen by other ophthalmic instruments, such as a slit-lamp. Also, by use of such microscopes, the effects of, for instance, normal aging and trauma may be monitored. These instruments also have been recommended for use in the evaluation of surgical procedures. One such microscope and its use is described by W. M. Bourne, B. E. McCarey and H. E. Kaufman, "Clinical Specular Microscopy", Journal of American Ophthalmology and Otolarynology, OP 743-752, Vol. 81, Sept-Oct 1976.
When used to examine the corneal endothelium, the first element of the optical system of the microscope is brought into direct contact with the corneal epithelium. This is accomplished by securing the microscope to a support system which permits bidirectional horizontal adjustment as well as vertical adjustment. Basically, such a support system includes an adjustment knob for changing the vertical position of the microscope relative to the base of the support system. The base of such a system includes a control lever to effect movement in the horizontal direction. Typically, the control lever is connected to a spherical element which cooperates with a flat friction surface. Rotation of the spherical element, via movement of the control lever, relative to the friction surface produces bidirectional movement in the horizontal direction. Support systems using this type of mechanism are disclosed in U.S. Pat. Nos. 2,940,357, 3,914,032 and 3,944,342.
Prior to corneal surgery, it is desirable to examine the corneal endothelium of an enucleated eye to determine its condition and compare it with the corneal endothelium of the patient's damaged eye. The comparison may be made using two different microscopes, each with its own illumination and photographic systems. That is, the patient's eye would be examined in vivo as described above and the corneal endothelium of the enucleated eye examined using another microscope system. One method of examining the donor's eye is described by William M. Bourne, "Examination and Photography of Donor Corneal Endothelium", Archives of Ophthalmology, American Medical Association, Vol. 94, Oct. 1976, pp. 1799-1800.
In an alternate comparison method the enucleated eye is examined with the same microscope optical and illumination system as that used to examine the patient's eye. However, in this application, the enucleated eye is supported in a vertical position so that its orientation is similar to that which the patient's eye assumes under examination. This is a rather awkward position and requires special holding apparatus secured to a head rest to properly orient and support the enucleated eye so that no damage is inflicted thereto.